In a conventional technology, in order to sterilize a bottle made of PET (polyethylene terephthalate) with hydrogen peroxide water, the bottle is guided into a chamber, the hydrogen peroxide water is sprayed within the chamber, and air is guided into the chamber to pass therethrough. According to such operation, even if the bottle has a complicated shape, mist of the hydrogen peroxide water uniformly adheres to a surface of the bottle to thereby uniformly sterilize the bottle surface (for example, refer to Patent Document 1).
Furthermore, it has been attempted to sterilize a preform in a preform stage before forming a bottle. That is, in a state in which a mouth portion of the preform is directed to a nozzle that is opened at a vertically downward of the preform mouth portion, a chemical agent such as hydrogen peroxide is jetted from the nozzle, the preform is thereafter guided into a heating furnace to thereby heat the preform to a temperature suitable for a blow molding process and enhance sterilizing effect, and thereafter, the preform is clamped by a forming mold and blow-molded into a bottle (for example, refer to Patent Document 2).
Furthermore, when the preform is sterilized in a preform stage, it has been attempted to put a number of preforms into which hydrogen peroxide water has been dropped respectively into a container, which is then sealed, and to sterilize inner and outer surfaces of these preforms with steam of the hydrogen peroxide water that is evaporated in the container at a time of transporting and maintaining the container. The preforms taken out from the container at a container receiving station is molded there into bottles in an aseptic state by a molding machine (for example, refer to Patent Document 3)
Still furthermore, there may be a case in which a use of sterilizing agent such as hydrogen peroxide or like is not desirable for sterilization of a preform. In such a case, as a method for sterilizing the preform with no use of the sterilizing agent, there has been provided a method in which water steam is blasted into to heat a preform to a temperature more than glass-transition point and maintain that temperature for a predetermined time for sterilizing the interior of the preform, and immediately thereafter, air is blasted into the preform to remove steam drain from the preform (for example, refer to Patent Document 4).